I took a glance at the encryption programs mentioned by LindaKauffman. My evaluation is superficial, based on the vendor's description on the vendor's website.
AxCrypt doesn't require the user to enter passwords, meaning AxCrypt holds the password. Since they don't make it clear where the secret infomation is kept, I assume the worst and assume they keep the secrets, and they can read my files. Also, if they go out of business, I won't be able to recover my files. Furthermore, to share a file with someone else, the recipient would have to download and install AxCrypt. Most corporate users are not allowed to install software on the computers issued to them by their corporations, so this program goes down in flames.
Certainsafe is cloud-based. So you have to trust Certainsafe. Also, if they go out of business your documents would be lost, and perhaps turned over to whoever buys their assets at a bankruptcy auction. The receipient of files would have to long into Certainsafe. This might disturb a recipient who just want the document emailed.
Folder Lock is for protecting folders or USB drives on a particular PC. It is not for encrypting files that are to be emailed.